On Mon, Oct 18, 2021 at 11:00 PM Maxim Kochetkov <fido_max@xxxxxxxx> wrote:
>
> Microchip EEPROM 24xx1025 is like a 24c1024. The only difference
> between them is that the I2C address bit used to select between the
> two banks is bit 2 for the 1025 and not bit 0 as in the 1024.
>
> Signed-off-by: Maxim Kochetkov <fido_max@xxxxxxxx>
> ---
> drivers/misc/eeprom/at24.c | 15 ++++++++++++++-
> 1 file changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
> index 305ffad131a2..6543ff6536aa 100644
> --- a/drivers/misc/eeprom/at24.c
> +++ b/drivers/misc/eeprom/at24.c
> @@ -96,6 +96,7 @@ struct at24_data {
> * Some chips tie up multiple I2C addresses; dummy devices reserve
> * them for us, and we'll use them with SMBus calls.
> */
> + u8 bank_addr_shift;
> struct at24_client client[];
> };
>
> @@ -123,6 +124,7 @@ MODULE_PARM_DESC(at24_write_timeout, "Time (in ms) to try writes (default 25)");
> struct at24_chip_data {
> u32 byte_len;
> u8 flags;
> + u8 bank_addr_shift;
> void (*read_post)(unsigned int off, char *buf, size_t count);
> };
>
> @@ -137,6 +139,12 @@ struct at24_chip_data {
> .read_post = _read_post, \
> }
>
> +#define AT24_CHIP_DATA_BS(_name, _len, _flags, _bank_addr_shift) \
> + static const struct at24_chip_data _name = { \
> + .byte_len = _len, .flags = _flags, \
> + .bank_addr_shift = _bank_addr_shift \
> + }
> +
> static void at24_read_post_vaio(unsigned int off, char *buf, size_t count)
> {
> int i;
> @@ -197,6 +205,7 @@ AT24_CHIP_DATA(at24_data_24c128, 131072 / 8, AT24_FLAG_ADDR16);
> AT24_CHIP_DATA(at24_data_24c256, 262144 / 8, AT24_FLAG_ADDR16);
> AT24_CHIP_DATA(at24_data_24c512, 524288 / 8, AT24_FLAG_ADDR16);
> AT24_CHIP_DATA(at24_data_24c1024, 1048576 / 8, AT24_FLAG_ADDR16);
> +AT24_CHIP_DATA_BS(at24_data_24c1025, 1048576 / 8, AT24_FLAG_ADDR16, 2);
> AT24_CHIP_DATA(at24_data_24c2048, 2097152 / 8, AT24_FLAG_ADDR16);
> /* identical to 24c08 ? */
> AT24_CHIP_DATA(at24_data_INT3499, 8192 / 8, 0);
> @@ -225,6 +234,7 @@ static const struct i2c_device_id at24_ids[] = {
> { "24c256", (kernel_ulong_t)&at24_data_24c256 },
> { "24c512", (kernel_ulong_t)&at24_data_24c512 },
> { "24c1024", (kernel_ulong_t)&at24_data_24c1024 },
> + { "24c1025", (kernel_ulong_t)&at24_data_24c1025 },
> { "24c2048", (kernel_ulong_t)&at24_data_24c2048 },
> { "at24", 0 },
> { /* END OF LIST */ }
> @@ -254,6 +264,7 @@ static const struct of_device_id at24_of_match[] = {
> { .compatible = "atmel,24c256", .data = &at24_data_24c256 },
> { .compatible = "atmel,24c512", .data = &at24_data_24c512 },
> { .compatible = "atmel,24c1024", .data = &at24_data_24c1024 },
> + { .compatible = "atmel,24c1025", .data = &at24_data_24c1025 },
> { .compatible = "atmel,24c2048", .data = &at24_data_24c2048 },
> { /* END OF LIST */ },
> };
> @@ -548,7 +559,8 @@ static int at24_make_dummy_client(struct at24_data *at24, unsigned int index,
> dev = &base_client->dev;
>
> dummy_client = devm_i2c_new_dummy_device(dev, base_client->adapter,
> - base_client->addr + index);
> + base_client->addr +
> + (index << at24->bank_addr_shift));
> if (IS_ERR(dummy_client))
> return PTR_ERR(dummy_client);
>
> @@ -689,6 +701,7 @@ static int at24_probe(struct i2c_client *client)
> at24->page_size = page_size;
> at24->flags = flags;
> at24->read_post = cdata->read_post;
> + at24->bank_addr_shift = cdata->bank_addr_shift;
> at24->num_addresses = num_addresses;
> at24->offset_adj = at24_get_offset_adj(flags, byte_len);
> at24->client[0].client = client;
> --
> 2.32.0
>
I wonder what the reason for this change in a standardized protocol was...
Anyway, can you rebase it on top of
git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux.git
at24/for-next please? We had a change in how the i2c client is
accessed and now this fails to apply.
Thanks!
Bart
